From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Performance comparison report between various Bentley and experimental car models.
| Identifier | ExFiles\Box 182\M19\ img150 | |
| Date | 18th March 1931 guessed | |
| -2- 65 to 70 m.p.h. and after that the Bentley went right ahead. For road work 27-EX. would not be left very much by the 8 Litre Bentley. That is, although we may increase our axle ratio to obtain slightly better maximum speeds, we should then definitely suffer on acceleration. We then carried out comparative tests between the standard car 26-EX. and 27-EX. In this case 27-EX. shewed up to be a very definite improvement except at the maximum speed, when the cars gave practically the same performance. Taking 26-EX. car as our standard Continental Touring car which we are delivering then the Bentley will leave this well behind in acceleration as well as on maximum speed. With the 6.5 Litre Bentley, with 27-EX. we could get several car lengths ahead, but the Bentley was better at maximum speed. The gearbox silence on the Bentley was a great improvement over the 6.5 Litre. They had no easy change but the third gear was relatively silent. SUMMARY. The 8 Litre Bentley is the best competetive car we have tried. It impressed us far more than the 8, 12, or 16 cyl. cars that we have tried. The torque reaction was manifest. There was also a vibration at 2800 r.p.m. which was objectionable, this we could not properly locate. At a genuine 75 m.p.h. the absence of any roar or fuss was very remarkable in comparison with the Maybach 12 cyl. The results of 27-EX. compared with the standard car shew an improvement which is very definite and which we ought to make use of. The points which have prevented us making use of this is that the carburetter either floods or starves hopelessly on the return (See separate report). Another point is that we have no proper scheme for getting petrol to the carburetters. On these tests we had to fit an electrical Autopulse petrol pump to enable the car to run. We are also investigating on the test bed further methods of maintaining the power at high speeds. The Bentley shews that you can run the big 6 cyl. up to 3700/3800 without trouble. Hs.{Lord Ernest Hives - Chair} | ||